000
FXUS63 KOAX 130813
AFDOAX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
313 AM CDT Tue Mar 13 2018
.SHORT TERM...(Today through Thursday)
Issued at 310 AM CDT Tue Mar 13 2018
Dry and warmer is the main weather story the next few days.
Surface high pressure was ridging south from the Northern Plains
toward the Mid Missouri River Valley region this morning, and will
continue to do so through this afternoon. As the high slides off to
the east later tonight and Wednesday, a return to south then
southwest low level flow will signal a significant warmup for the
middle of the week.
Lots of sunshine this afternoon should help to offset limited mixing
regime under surface ridging, but highs will remain below normal for
the middle part of March. That changes on Wednesday as southwest
winds kick in early and continue through the afternoon, adding an
element of compressional warming. We will still see plenty of
sunshine, and 850 temps gain about 8C from this afternoon through
Wednesday afternoon. Thus highs approaching 20 degrees warmer than
this afternoon are not out of the question.
Meanwhile an upper low currently in the Eastern Pacific will swing a
trough into the Pacific Northwest by Wednesday afternoon. A strong
shortwave rotating east then northeast around the base of the
trough will promote surface cyclogenesis in eastern Colorado
during the day Thursday. Besides increasing mid and high clouds in
diffluent flow ahead of shortwave, main impact for our area on
Thursday will be winds turning to an easterly direction north of
a strengthening baroclinic zone across Kansas. This flow and some
cloud cover should keep highs 5 to 10 degrees cooler Thursday
afternoon.
.LONG TERM...(Thursday night through Monday)
Issued at 310 AM CDT Tue Mar 13 2018
Precipitation chances return to the forecast much of the longer term
period, with Saturday the most-likely dry day Friday through
Monday.
Mid level shortwave is forecast to deepen into a closed low as it
slides east into the Plains Thursday night through Friday night.
Isentropic upglide over Kansas frontal boundary will likely lead to
a good chance for rain Thursday night as moisture transport into
eastern Nebraska and southwest Iowa continues. Some weak instability
is noted in model output in southeast Nebraska, so some isolated
thunderstorms are possible there Thursday night. Also, current
indications suggest surface temps may slip below freezing for a time
in northeast Nebraska late Thursday night and Friday morning,
resulting in a period of potential freezing rain. Upper low is
forecast to drift over our area Friday night and sufficiently
cool mid and lower atmosphere for a change to snow later Friday
night.
Upper low should be moving east on Saturday allowing a respite in
precipitation for a day or so. However another wave rotating through
the Plains will bring precipitation chances back to our area,
especially Sunday night and Monday. And again, temperature profiles
support rain initially, but a change to snow is possible as
atmposphere cools later Sunday night and Monday morning.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1140 PM CDT Mon Mar 12 2018
Surface high pressure will remain in place over the region through
the forecast period. Other than some passing mid and high-level
clouds, expect prevailing VFR conditions.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...Dergan
LONG TERM...Dergan
AVIATION...Mead